There is a distance between left and right eyes of an observer, which results in a small difference between visual angles of the two eyes. Such difference may cause sceneries observed by the left and right eyes to have a slight displacement, so as to generate a three-dimensional image in the observer's cerebrum.
Recently, naked-eye three-dimensional display techniques gain more and more attentions from people. Display panels are developed increasingly towards three-dimensional displaying. Three-dimensional display technique for mobile telephone panels particularly gains attentions. Because the mobile telephone panels have small sizes, it is easily to make the observer feel dizziness due to switching during three-dimensional displaying. Accordingly, a three-dimensional image may not be observed. Therefore, a three-dimensional displaying with tracking technique is selected, so that the observer may observe an optimal three-dimensional image when the mobile telephone is observed at different positions. Such tracking technique brings a new breakthrough to the three-dimensional display technique for mobile telephones.
In an existing mobile telephone, a three-dimensional display tracking technique tracks the observer's face using a camera arranged in the mobile telephone. Position information of the observer's face is caught via the camera, and then an optimal three-dimensional display effect is provided to the observer after image processing and software debugging.
However, this existing three-dimensional display tracking technique has many limitations for a display apparatus with a smaller display panel such as the mobile telephone. Firstly, the camera of the mobile telephone is generally mounted on the back face thereof, while the display panel is mounted on the front face thereof. However, the existing three-dimensional display tracking technique needs the camera and the display panel to be located at the same side. Therefore, the mobile telephone with the display panel mounted on the back face thereof may not track different positions of the observer accurately. Secondly, a tracking technique for the existing camera needs a relatively complex running process such as detecting, recognizing and tracking of an image, which brings a large number of data processing and occupies more resource for computing. Therefore, the requirement of a quick tracking speed may not be met.